Add metadata to canvas

- [ ] Add this Github as a link
- [ ] Add version number
- [ ] Add current user's as an avatar somewhere at the top left with their username

Mockup(doesn't have to look exactly like this, just an idea):

The issue names no files or tests, so start by locating the canvas UI entry point and checking how the current user and application version are exposed. Done means the canvas shows a GitHub link, version number, and the current user's avatar with username near the top left, consistent with the mockup's intent.

Written by the indexing model from the issue text.